Question re G2 and/or Thermal Shutdown and/or P61

Sorry about the ambiguous title of the thread, but I'm not sure exactly what the issue I'm having is. It could be something to do the the SF G2 Nitrolon, the P61 lamp assembly or the thermal shutdown of (SF) CR123 cells (or all three).

If someone has experienced this combination, i.e. thermal shutdown when running a P61 in a G2 Nitrolon, then you may be able to help verify some things:

I've just been running this combination flat-out in an attempt to get some data for the thread about LunarModule's exploding PM6. I don't normally push things to the limits, and so have just experienced some things I'm not familiar with.

Specific questions:

(1) At 12 minutes runtime (fresh, "matched" batteries), output dimmed from bright to off in about 4 seconds. I turned it off, let it cool for about 20 minutes, then it was able to produce bright light again. I expect this means that one or both of the batteries had entered thermal shutdown. Does that sound right, i.e. is thermal shutdown a process that takes place over a few seconds, then resets in a relatively short time if the batteries are allowed to cool?

After it had cooled, I took the batteries out and there was a very powerful smell which I am not familiar with. It smelled nothing like the solvent smell that is common with CR123s. I would describe it as acrid and overpowering. I vented the room and left it for about 20 minutes, after which it was tolerable. I inspected the batteries, and there were no signs of leakage or damage. I checked voltage and "flash amps", and both were AOK. After separating all the parts of the G2 for a while to let them air, it seems that all parts, and the batteries, have this horrible smell - making it hard for me to work out where it is coming from. So:

(2) Is it typical for CR123 batteries that get very hot, or enter thermal shutdown, to produce an acrid smell?

If anything, the smell seems to be strongest at the bulb. I've also noticed a blob of solid white stuff where the central spring connects to the lamp assembly. I hadn't noticed it before, and by contrast, there isn't one on my P60. It looks like it may be adhesive that I just hadn't noticed before. So:

(3) Can anyone with a P61 confirm that thay have this white blob?

It could even be that this white blob is adhesive, and it just got so hot that it has produced this awful smell. It may even be the Nitrolon body, because the smell is so pervasive that it comes from the whole external length of the tube - though I doubt this, because I didn't notice the smell until I first opened up the G2.

Anyway, most general question of all:

(4) Has anyone else experienced this or something similar, and what did you conclude had happened?

Thanks in advance.

I've run plenty of DL123A & SF123A to thermal shutdown with the N62 in the 12PM and M4 etc. The batteries do smell but it wasn't a nasty smell. Just a lot more obvious smell that you get when you open up a CR123A flashlight anyways.

Perhaps you should repeat your experiment to see whether another pair of SF123As performs the same?

Al

Size15's said:

Perhaps you should repeat your experiment to see whether another pair of SF123As performs the same?

Click to expand...

I expect I will be repeating it, but (having just smelled everything again) I'm still not at all sure it was the batteries - still smells strongest at the bulb.

I'm a bit wary of running the bulb, just in case this white blob has appeared due to some sort of fault. Do your P61s have this white blob? I have a suspicion that the white blob was there all the time, but I also suspect the smell is coming from it. It may not be critical, but I'd like to know, just to put my mind at rest.

TIA.

The blob of white stuff is standard that I can tell.

Have you tried the P60 that came with your G2, or maybe purchase a new P61 to try, they are not expensive.

You will need to find out which of these parts are causing the problem.

(3) Can anyone with a P61 confirm that thay have this white blob?

Click to expand...

My P61 also has this "blob."

Ha you made me laugh I do not laugh very often.
I only found 1 SF P61 and it has the white blob it has been used but not lately. Too bad we can't post "smells" I like the smell of 123's :huh2:
but they seem to smell the same no matter what light I am using. I must ask, did you hold the G2 while doing your test? I have never left one on without holding it. I do think ( I know, I just typed "think" cuz i'm not looking for a debate) lights get hotter when left alone and I have no idea as to how hot it has to get before starting to melt the G2 or whatever lubricant that might be involved.
Topper

Topper said:

Ha you made me laugh I do not laugh very often.
I only found 1 SF P61 and it has the white blob it has been used but not lately. Too bad we can't post "smells" I like the smell of 123's :huh2:
but they seem to smell the same no matter what light I am using. I must ask, did you hold the G2 while doing your test? I have never left one on without holding it. I do think ( I know, I just typed "think" cuz i'm not looking for a debate) lights get hotter when left alone and I have no idea as to how hot it has to get before starting to melt the G2 or whatever lubricant that might be involved.
Topper

Click to expand...

I was thinking it would be nice to post smells! Here's an attempt to describe the smell:

It's not like as in poo-poo, where it's just unpleasant. It's more like as in petrol or an acrid smell like smoke from burning rubber. Not that it smells like that - it just has the same sort of effect, where you can't help but think it's a naughty chemical. I think I got a bit light-headed and there was a slight sensation in my chest for a while (just as you might expect if getting a whiff of burning rubber or petrol), but it could have been my imagination. Either way, my spider senses told me I needed to leave the room for a while!

And yes, you got me. I am leaving it unattended, on a thermally insulated surface. I don't think there is a debate - we clearly agree that it is going to get hotter that way, and that's exactly what I am trying to cause.

Thank you everyone for your input.

I'll probably just carry on regardless tomorrow (it's 3:50am here now), but I'll check to see if anyone else has posted a similar experience here first.

My bedtime now but I can (in a day or so) run a SF P61 in a G2 for 12 minutes to see if mine shuts down (I will not hold it I promise) and if so let it rest for 20 and repeat. I will make sure as I can as to the cells being 100% according to the tester I have; and I will use SF 123's. If it shuts down at 12 minutes give or take I will attempt to dump the cells quickly to get a temp reading. And I will sniff away of course.
Topper

Do you have a volt-ohm meter (VOM) with an ammeter function? This would reveal excessive current draw by the lamp.

If you don't know how to do it, get yourself a VOM with an ammeter function (they usually have THREE places to plug in the probes; negative, positive and ammeter mode). Remove the tailcap of the light, connect one probe to a bare aluminum part of the flashlight body and the other probe to the negative contact of the battery. The light will turn on, and the meter will tell you how many amps it's pulling.

Look at your lens (plastic window). It must be melting to some degree, and that can smell. The P61 LA puts out some serious heat.

Bill

Bullzeyebill,

Thanks, I've done just that. Now that things have aired overnight, the smell is still on all the components, but the inside of the bezel absolutely Mings to High Pong. The lens looks okay at a glance, but if I try reading through it, I get the same effect as looking through old glass windows that have run.

I'm 99.9% confident the smell is coming from the inside of the lexan lens which had started to melt.

Thanks again to everyone for your input.

Topper, thanks for the offer to try an replicate it, but I'm confident it was the lens now, so no need. No point in melting yours.

Admin / Mods: I'm happy for this thread to be closed, if you wish.

You might want to consider getting a UCL lens from flashlightlens.com all my G2's have one.
Topper

I'm running a P91 behind a Lexan window, and will certainly try to avoid overheating the plastic. I wonder of the G2 head/bezel itself was partially charred from the heat as well contributing to the unusual smell. Should Lexan windows be avoided altogether with the HOLA's?

Paladin

Paladin said:

I'm running a P91 behind a Lexan window, and will certainly try to avoid overheating the plastic. I wonder of the G2 head/bezel itself was partially charred from the heat as well contributing to the unusual smell. Should Lexan windows be avoided altogether with the HOLA's?

Paladin

Click to expand...

No.
The issue is that your use (& conditions of use etc) is producing too much heat. If you are needing to use the HOLA for long bursts of constant-on then certainly use a G2Z bezel (or if you so desire, modify your G2 bezel to use a glass window).

Lexan in several situations is a far better window for a flashlight being used in harsh conditions. I still use a Lexan TurboHead on one of my M6's because I know it won't break when dropped etc.

Al

My three P61's all have the white blob. I've had no problems with thermal shutdown or the window melting, but I've never run my G2/P61 combos for more than ~5 minutes, either.


Cheers. :buddies:

HOLA's used with turbo heads are less affected by heat from the lamps. There is a large internal area for heat to discipate before it reaches the window, compared to standard size bezels.

Bill